Yamaha WR450F

First generation (WR400F, 1998)

Yamaha introduced the WR 400F in 1998. The 400F is a 400 cc four-stroke off-road motorcycle produced for three years, beginning in 1998 and ending in 2000 (only the YZ was upgraded to 426 cc in 2000). The WR400F is related to the YZ400F, a motocross model. Like the YZ400, it was considered to be a groundbreaking model in motorcycle history, ushering in the four-stroke era which ended the dominance of two-stroke engines in motocross and offroad racing. While many modern performance four-stroke dirt bikes have been criticized for excessive rebuild costs and short motor lifespans, the Yamaha WR400F has an impressive record of reliability, often attributed to its steel valves and generous oil capacity.

Second generation (WR426F, 2001)

Rear: 120/90-18

Third generation (WR450F, 2003)

Rear: 11.6-in travel Rear: 245 mm disc Rear: 110/100-18 64M

For 2003, the engine displacement was increased to 449 cc, the fuel tank was reduced to 2.6 gallons and an electric starter was added as standard equipment. The 2005 WR weighed in at 244 pounds dry, the seat height was reduced to 38 inches and the fuel tank was decreased to 2.1 gallons. The 2006 WR weighed in at 249 pounds dry

A limited production version of the WR450F was the WR450F 2-Trac, which featured 2-wheel drive. The gearbox output sprocket drove a short, fully enclosed chain to a pump, which in turn pushed the oil to the front hub via the pipe and back via the parallel pipe. A maximum of 15% of the power was transmitted to the front wheel at any time. Yamaha planned on building 250 2-Tracs in 2004, but only a few were built, which were used for enduro racing. 2006 was the last year of the steel frames.

The 2003 and 2004 models were red sticker bikes in California.

Fourth generation (WR450F, 2007)

Rear: KYB shock with 12 in travel Rear: 245 mm disc Rear: 110/100-18 64M For 2007, the WR gained an aluminum frame dropping the weight from 249 to 246 pounds. In addition to the aluminum frame, the 2007 WR450F saw a revised dry-sump engine, with a new balancer, cylinder head, and camshafts with less lift and duration than previous generations and restyled plastics. 2009 saw new graphics, and 2010 was not sold in the US.

Fifth generation (WR450F, 2012)

Rear: KYB shock with 12 in travel Rear: 245 mm disc Rear: 120/90-18 65M After 3 years of design, the all-new 2012 WR450F was released and featured a 2012 YZ250F frame, KYB SSS forks, fuel injection, and an altered motor position. Per Yamaha's designers, the only modifications required to the YZ250F chassis were updated motor mounts. The engine was rotated back to move the center of gravity and improve handling

Sixth generation (WR450F, 2016)

Rear: 12.5 in travel Rear: 245 mm disc Rear: 120/90-18 64M For 2016, the WR was given the reverse slant, 4-valve, fuel injected motor previously available in the YZ450F since 2010. Yamaha also introduced a new model, the YZ450FX, a more Enduro competition oriented version of the off-road 450 utilizing more design elements of the motocross model such as stiffer suspension while maintaining electric start and the 18" rear wheel.

For 2017, the WR450F largely remained the same, except for modifications to the air box cover as well as a change from silver to black rims.

For 2018, the WR450F remained similar to the 2016-2017 models, with a large distinction being that the bike was no longer available to register as green sticker in the state of California. 2018 also saw the removal of the kick starter.

https://www.yamahamotorsports.com/off-road/models/2016/wr450f

Seventh generation (WR450F, 2019)

Rear: 12.5 in travel Rear: 245 mm disc Rear: 120/90-18 The 2019 WR450F saw a more powerful motor & updated frame.

Seventh generation (WR450F, 2021)

The 2021 WR450F saw new cylinder head, camshafts, piston and connecting rods as well as a revised chassis.

References

References

1. (2001). "2001 Yamaha WR426F". Motorcycles.com.
2. (2002). "2002 Yamaha WR426F". MotorcycleUSA.com.
3. "2007 Yamaha WR450F Specifications+Comparison".
4. (2005-05-23). "2005 WR450F vs CRF450X Comparo Conclusion". Motorcycle USA.
5. Blezard, Paul. "Yamaha WR450F 2-Trac - Review". www.mcnews.com.au.
6. (August 2006). "Owner's Service Manual WR450FW".
7. (January 2026). "2007 Yamaha WR450F WR250F". Motorcycle USA.
8. (January 2012). "Owner's Service Manual WR450FB".
9. (2012). "WE RIDE THE ALL-NEW YAMAHA WR450F: A YZ250F WITH A YZ450F ENGINE". Motocross Action Magazine.
10. (2016). "2016 Yamaha WR450F Off-Road Motorcycle - Specifications". Yamaha Motor Corporation USA.
11. (14 June 2017). "2018 Yamaha WR450F First Look 6 Fast Facts".
12. (2016). "2020 Yamaha WR450F Cross Country Motorcycle - Specifications". Yamaha Motor Corporation USA.
13. "2019 vs 2018 Yamaha WR450F Chassis".
14. "2021 Yamaha WR450F Review".